Washington — Rick Santorum’s 16 years in the House and Senate are giving rivals plenty of scope for attack.

Heading into Wednesday night’s debate, Mr. Santorum was vying with Mitt Romney for frontrunner status in the Republican presidential field, but wound up taking a bashing over his record in Congress.

From “pork” projects to tough compromise votes on must-pass bills, the former senator from Pennsylvania was pressed to defend decisions revisited and rescored in the glare of a presidential campaign being fought in a new era of hyperpartisanship.

Earmarks – in Santorum’s early years, widely viewed as a mark of a lawmaker’s clout and commitment to voters – are now banned. President Bush’s No Child Left Behind law, hailed as a triumph of bipartisanship and presidential leadership, is now under fire by both parties.

A firebrand who never cooled off, Santorum rubbed many former colleagues the wrong way – few are lining up to support him – and today is frequently portrayed as an uncompromising culture warrior. But in Congress, Santorum also established a legislative record that bridged party lines on issues ranging from welfare reform and protecting unions to support for children with disabilities, notably more federal funding for autism research.

Santorum swept into the House in 1991 with an insurgent GOP class set on challenging nearly 40 years of Democratic control.

In his first year, he helped found the “Gang of Seven,” a group of seven freshmen, including Rep. John Boehner of Ohio, that aimed to shine a light on abuses of a Democrat-controlled House. They helped turn member overdrafts at the House bank into a national scandal that drove dozens of House members into retirement or defeat in the 1992 campaign cycle.

Many insurgent Republicans of his era later softened their tone. Others adapted, easing into the big-spending, big-government bureaucracy they once opposed. But Santorum continued this outsider perspective well into his 16 years on Capitol Hill, railing against congressional perks, pay hikes, and, famously, even the Senate barbershop, which he said should be privatized.

When Republicans finally took back the House in 1995, Santorum had just won a seat in the Senate, where his brash, outspoken style appeared to some colleagues jarring and even toxic.

“Such statements are harsh and severe, to say the least,” said Senator Byrd, viewed at the time as the guardian of Senate tradition. “And when made by a senator who has not yet held the office of senator a full year, they are really quite astonishing.” Byrd called it “the poison that has settled in upon this chamber” – a term picked up by leaders on both sides of the aisle.

But Santorum’s record over 12 years in the Senate and two terms in the House does not fall out neatly along partisan lines. A Catholic with strong ties to Evangelicals, Santorum got his start in a district of struggling mill towns in the steel valley southeast of Pittsburgh.

“Unlike most congressional Republicans, I represented a lot of people who were poor, but with rich traditions; bitter, but still proud,” he wrote in his 2005 book, “It Takes a Family” – a counterpoint to then-First Lady Hillary Clinton’s 1996 book, “It Takes a Village.”

The liberal vision doesn’t work to improve their lives, he wrote. But the conservative vision, too, had its limits.

“I came to the uncomfortable realization that conservatives were not only reluctant to spend government dollars on the poor: They hadn’t even thought much about what might work better,” added Santorum, who used congressional earmarks to direct more resources to struggling manufacturing towns.

A champion for social conservatives, Santorum sponsored the Partial-Birth Abortion Ban Act of 2003, which criminalized ending late-term pregnancies. In 2005, he rushed to Terry Schiavo’s bedside in a bid to involve the US Senate in blocking a family decision to terminate her life.

According to a study by the Sunlight Foundation, he ranked No. 1 during his years in the Senate in the use of phrases such as abortion, fetus, and womb.

“The United States Senate deals with a wide range of issues, both foreign and domestic, but the ones that preoccupied Rick Santorum the most during his tenure appear to have been gynecological,” says Lee Drutman, senior fellow at the Sunlight Foundation, in a Jan. 6 blog reporting on a content analysis of the Congressional Record over Santorum’s years in the Senate.

As a member of the House Ways and Means Committee, Santorum helped define the Republican position on welfare reform. In a rare move, Senate GOP leaders assigned him to manage the floor debate on welfare reform in his freshman year, even though he was not a member of the lead committee on the issue.

After President Clinton vetoed the previous two welfare reform bills, “We overcame [then Speaker] Newt Gingrich, who didn’t want to give Clinton a third chance at welfare reform,” says Ron Haskins, a former White House and congressional adviser on welfare issues and former Santorum aide.

“Santorum is well known for making statements that seem intemperate,” adds Mr. Haskins, who is now with the Brookings Institution, “but he is a quick study and a great negotiator.”